Which two numbers need to be interchanged to make the following equation correct?
$$27 − 8 \times 4 − 3 \div 2 = 1$$

$$27-8\times\ 4-\frac{3}{2}=1$$

A. 2 and 8

$$27-2\times\ 4-\frac{3}{8}=1$$

$$27-8-\frac{3}{8}=1$$

$$19-\frac{3}{8}=1$$

$$\frac{16}{8}=1$$

$$2=1$$

B. 2 and 3

$$27-8\ \times\ 4-\frac{3}{2}=1$$

$$27-8\times\ 4-\frac{2}{3}=1$$

$$19\times\ 4-\frac{2}{3}=1$$

$$76-\frac{2}{3}=1$$

$$\frac{74}{3}=1$$

$$24.667=1$$

C. 3 and 4

$$27-8\times\ 4-\frac{3}{2}=1$$

$$27-8\times\ 3-\frac{4}{2}=1$$

$$27-24-\frac{4}{2}=1$$

$$3-\frac{4}{2}=1$$

$$3-2=1$$

$$1=1$$

D. 8 and 4

$$27-8\times\ 4\ -\ \frac{3}{2}=1$$

$$27-4\times\ 8-\frac{3}{2}=1$$

$$23\times\ 8-\frac{3}{2}=1$$

$$23\times\ \frac{5}{2}=1$$

$$\frac{115}{2}=1$$

$$57.5=1$$

Hence option C is the correct answer .